


Mutuality

by SaraJaye



Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Breast Worship, Breastplay, F/F, Fantasizing, Fluff and Smut, Horny Mercedes, Large Breasts, Mutual Pining, Pre-Timeskip | Academy Phase (Fire Emblem: Three Houses), Sauna, Teacher-Student Relationship
Language: English
Status: Completed
Published: 2020-07-17
Updated: 2020-07-17
Packaged: 2021-03-04 20:53:38
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,627
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25322680
Author URL: https://archiveofourown.org/users/SaraJaye/pseuds/SaraJaye
Summary: The line between teacher and student is blurrier when the teacher feels the same way.
Relationships: Mercedes von Martritz/My Unit | Byleth
Kudos: 49
Collections: FE3H Kink Meme





	Mutuality

**Author's Note:**

> **Prompt:** some consensual boobie loving between f!byleth and mercedes would be lovely! doesn’t matter how it happens, just let them suck each other’s nips. what happens next is up to you, but no lactation, please.
> 
> for the 3h kink meme

It's almost shameful, how much she thinks about her professor's breasts.

Mercedes has been well aware of her preferences since she was fourteen, as she started to notice both cute boys and beautiful girls. To her, the Goddess Tower legend has always been about two people, not just a man and a woman. She's never been shy about her preferences either, when such things come up, and most people accept it. Or at the very least don't complain.

And there's certainly nothing wrong with admiring someone's attractive body, either. But this isn't just someone, this is her _teacher._ Someone in a position of authority over her who commands respect and obedience, someone a _good_ student wouldn't sit there staring at like a thirsty fool.

_This is so silly. It's not as if I've never seen a teacher's breasts, Professor Manuela's dress leaves so little to the imagination,_ she thinks. And Professor Manuela is _striking_ for a woman of her age, absolutely lovely. But she's never once had a dream about Professor Manuela that left her breathless and sweaty and damp between her legs.

She's lost count of how many such dreams she's had of Professor Byleth. Sometimes it's a wonder she can even focus on the lessons, or that no one's noticed her cheeks going bright red whenever Professor Byleth looks at her. When the professor invites her to tea, it's all Mercedes can do not to ask if next time they can meet somewhere more private. Like her bedroom.

_She's your teacher. This isn't right._ But the more she reminds herself of this, the less it sticks, and the more she has to force herself to look anywhere but at Professor Byleth's breasts during lessons, or any time they talk. Thankfully, the professor is oblivious to this, right?

"Mercedes." _Ah!_ She's in class right now, she remembers, and Annie and a few others are looking at her. _Oh, dear._ She swallows, sitting up straight, pulling her paper closer to herself.

"My apologies, professor. I was-"

"It's all right. I know these lectures can get a bit boring," the professor says. Her gaze lingers on Mercedes, and for a split second it seems to travel lower than her face. Is her uniform misbuttoned? Is her hair tangled? Did she spill something during lunch that afternoon?

"A _bit?_ " Felix scoffs, breaking her line of thought. "It's a waste of valuable training time." Ingrid swats him, and the professor gives both of them a Look.

"We've only five more minutes left, class, and then you're free." She glances at Mercedes, and Mercedes's cheeks burn. "However, I would like to see _you_ afterwards." _Oh..._ Mercedes' heart races, she's not sure whether to be afraid or hopeful. Annie looks like she wants to say something, her eyes narrowed, but she keeps her mouth closed.

Five minutes feels like five moons before the lesson finally ends and the classroom empties. Mercedes, hands clutching her shawl, makes her way stiffly to Professor Byleth's desk.

"I'm very sorry for my lack of attention during class, professor," she murmurs. "I know this is important, but-"

"You don't need to pretend anymore," Professor Byleth interrupts. "I've noticed." _Eep!_ Mercedes grips the fabric more tightly, stifling a whimper, trying to scramble for an excuse for all of half a minute before she gives up.

"I'm _so_ sorry, I know it's not appropriate, I shouldn't be _looking_ at you in such a way," she rambles, "I swear to the goddess, I have _much_ more self-control than this, I would _never-_ you're my _teacher,_ I'd never cross that line!"

She swears she sees the hint of a smile on Professor Byleth's face just then.

"Your teacher, yes," she says. "That means I've been just as inappropriate. I'm in a position of authority over you, and yet I can't help staring either." Mercedes squeaks, her whole body going flush.

"Earlier," she murmurs, "you were looking at..."

"Not just today." Professor Byleth chuckles a little. "Dimitri told me you were very aware of your surroundings, but it seems I've hit your blind spot. We've shared the sauna together more than once, and I've seen you in your loungewear. And that shawl doesn't hide as much as you think it does."

Mercedes isn't sure whether to feel relieved or stupid. On one hand, her desires aren't as one-sided as she thought they were. On the other hand, yes, she is usually very aware of her surroundings. How could she have missed something like _this?_ Or had she been so locked into the idea that her feelings were wrong that she didn't consider such a possibility?

Or that Professor Byleth wasn't as immune to feelings as she first let on?

"Come to my room tonight, professor," she almost whispers. "Late, after everyone else has gone to bed."

"Too risky," the professor says. "I know of a more private place, where we don't risk anyone hearing us."

The sauna's steam function is turned off at night, and the sauna boss leaves a key under the doormat "just in case." Mercedes arrives, still in her school clothes, to find her professor holding up the key with a smile. Heart pounding, Mercedes follows her into the empty room, relieved to find it's actually quite chilly inside. The door closes, and the two women come together in a passionate kiss.

"I can't believe we're _doing_ this," Mercedes whispers, a giggle escaping her when they break for air. "Not just sneaking in here late at night, but..."

"Believe it." Professor Byleth... _no, Byleth,_ Mercedes thinks. During the day they're teacher and student, but right now they're two women giving into their desires. They undress each other quickly, layer after layer falling to the sauna floor until Byleth's glorious breasts are fully revealed to her at last. Byleth moves closer, arching her chest forward, and Mercedes extends an eager hand to touch her.

"Wow! You're even softer than I imagined," she whispers, cupping a breast in each hand and squeezing gently. "Is this okay...?"

"Mm..." Byleth tilts her head back. "More than okay. Don't hold back, Mercedes, we've both been wanting this for too long-!" Her last word is cut off as Mercedes lowers her head, brushing her lips over the slope of her right breast, circling her tongue around a hard, dark pink nipple. " _Ah_ , Mercedes-!" Fingers catch in her unbound hair, and Mercedes draws the nipple into her mouth, suckling slowly, her hand continuing to caress and squeeze Byleth's other breast.

It's like nothing she could have ever dreamed of, even her steamiest fantasies can't compare to this. Byleth's gasping and squirming under her touch, and the sharp tang of her arousal soon fills Mercedes's nostrils. She briefly considers moving lower, but she can't bring herself to move away from the woman's breasts.

"I want to try something," she murmurs against Byleth's flesh. Her fingers squeeze one nipple, her teeth gently pressing into the other as she carefully tugs on it. The other woman lets out a near-scream, fingers tightening in her hair; Mercedes presses her teeth a bit more firmly before drawing the nipple back into her mouth and sucking _hard._ Her name and various litanies spill from Byleth's lips, Mercedes can tell she's getting close and ups the ante, hand and lips and tongue working faster and more feverently.

Her efforts pay off moments later, when Byleth's body tenses and she lets out a shriek, Mercedes feeling the heat of release racing through her and the quickened pulse under her skin. She keeps at it until Byleth begins to come down, then moves back just a bit. The sight of her normally cool and emotionless-seeming professor so flushed and sweaty is a lovely one, and Mercedes is more aware than ever of the heat between her own legs by now.

"You're incredible," Byleth whispers. "Now, let me return the favor." She lowers her own head to Mercedes' left breast, Mercedes biting down on her hand to stifle a shriek as she feels the brush of the other woman's lips and the slick caress of tongue against her nipple. She's never bothered to wonder about Byleth's sexual past, since it's none of her business, but if she's never done this before she must have done her research somewhere. Or possibly had the same fantasies as Mercedes did. 

Either way, Mercedes's breasts tingle with every caress, every lick, every kiss until the wetness is trickling down her thighs. She's getting closer, closer, body tightening in anticipation until she's overcome with heat, the climax racing through her as she throws her head back with a yell.

She's not sure how much time passes before she comes down, leaning against Byleth with a deliriously happy sigh. For a brief instant she wonders if this is all just one of her dreams again she's about to wake up, but Byleth kisses her, and she knows it's real.

"We should go back," Byleth says after a long, blissful silence. "It's already late enough, and tomorrow is another early lesson." Mercedes sighs, reluctantly pulling free of their embrace.

"I know. I wish we didn't have to, but..."

"We'll have plenty more nights like this, I promise," her lover says, and Mercedes's heart races in anticipation. They quickly get dressed, and she walks Byleth back to her room.

"Next free day," Byleth whispers, "meet me in my quarters. We'll have plenty of time and space then." Mercedes nods, and they kiss goodnight briefly before she hurries back to her room, closing the door behind her and collapsing into bed. Her clothes still smell like Byleth and the sauna, and she's in no hurry to take them off.

Three days seems like a long time, but she knows it will be worth the wait.


End file.
